Electrically heated hairsetter

ABSTRACT

An electrically heated hairsetter wherein a plurality of solid, plastic, hair curlers are heated over a plurality of posts; each curler adapted to fit intimately over the post of the appropriate diameter. The posts are part of the casting which includes an electric heated element in its base, and which is cast therewithin in a single casting operation. The base of the heater element portion is configured to fit beneath the top panel of the hairsetter cabinet by cooperating with legs beneath the top panel in a relative sideways motion relationship, with provision for driving a locking pin so as to hold the heater element portion and top panel fitted together. A thermostatically controlled state-of-temperature indicator is mounted within the cabinet of the hairsetter and is of an appropriate material so as to approximate the heating characteristic of the curlers placed over the posts, and closes a switch at a predetermined setting to provide an indication that the hair curlers are ready for use.

United States Patent [72] Inventors Allan Trevor Thomas Downsview, Ontario; James Spencer Vernon, Scarborough, Ontario, both of Canada [21] Appl. No. 801,492 [22] Filed Feb. 24, 1969 [45] Patented Oct. 5, 1971 [73] Assignee Samson-Domimion Limited Scarborough, Ontario, Canada [54] ELECTRICALLY HEATED HAIRSETTER 7 Claims, 20 Drawing Figs.

[52] US. Cl 219/222, 132/33 R, 132/39, 219/242, 219/506, 219/521 [51] Int. Cl 1105b 1/02, A45d 2/12, A45d 4/12 [50] Field of Search 21 9/222-226, 506, 520, 521, 242; 132/33 R, 39

[56] References Cited UNITED STATES PATENTS 2,525,274 10/1950 Schleimer 219/222 UX 3,257,541 6/1966 .lorgensen... 219/222 3,410,985 1 1/ 1968 Giacchero 219/242 X 3,415,254 12/1968 Brock et al.

219/222 X 3,472,245 10/1969 Abe 219/222 UX 3,483,876 12/1969 Planel 132/33 R Primary Examiner-A. Bartis Attorney-Douglas S. Johnson ABSTRACT: An electrically heated hairsetter wherein a plurality of solid, plastic, hair curlers are heated over a plurality of posts; each curler adapted to fit intimately over the post of the appropriate diameter. The posts are part of the casting which includes an electric heated element in its base, and which is cast therewithin in a single casting operation. The base of the heater element portion is configured to fit beneath the top panel of the hairsetter cabinet by cooperating with legs beneath the top panel in a relative sideways motion relationship, with provision for driving a locking pin so as to hold the heater element portion and top panel fitted together.

A thermostatically controlled state-of-temperature indicator is mounted within the cabinet of the hairsetter and is of an appropriate material so as to approximate the heating characteristic of the curlers placed over the posts, and closes a switch at a predetermined setting to provide an indication that the hair curlers are ready for use.

PATENTED HGT 5197:

SHEET 1 0F 6 PATENTED um 51911 $610,878

' sum 2 BF 6 I N VIiN H )R. ALLAN T. THOMAS.

PATENTEDIJCT Sum 3510.878

- SHEET 5 [IF 6 FIG.14.

118 IIO(Bl-METALLIC ELEMENT) FIELD OF THE INVENTION This invention relates to an electrical household appliance; more particularly, the invention relates to an electrically heated hairsetter of the type wherein hair curlers are heated over posts for subsequent winding, while hot, into the hair.

DESCRIPTION OF THE PRIOR ART Previously, when it has been desired to curl the hair using a heated curler or roller, the most common method has been to immerse the curlers or rollers in a heated liquid--usually water--from whence the curlers, when hot, are withdrawn and placed in the hair. Other apparatus of the type known as a curling iron has also previously been used, such apparatus usually comprising a long somewhat tapered mandrel with a spring-loaded half-sleeve associated therewith and having an electrically heated element within the mandrel. More recently, Canadian Pats. 771,958 and 779,709 issued Nov. 21, I967 and Mar. 5, I968 respectively to Arne B. Pedersen (and US. Pat. No. 3,257,541 issued June 21, 1966 to Niels C. Jorgensen and assigned to Pedersen, corresponding thereto) have taught an electrically heated apparatus for heating the hair. That apparatus basically comprises a hair curler in the form of a container in which there is inserted a heat accumulating material having a high-melting heat, and which liquifies when heated and is such that it slowly gives up its heat when removed from the heating apparatus and placed in the hair.

SUMMARY OF THE INVENTION An improved apparatus for curling and setting the hair, and the heating apparatus associated therewith, has been developed and is described herein. The apparatus of this invention is such that all of the heated curlers, when ready to be placed into the hair, are of substantially uniform temperature, and are easily removed from the heating apparatus for winding into the hair. Additionally, the curler associated with the apparatus described herein is one of an homogeneous nature whereby there is no risk that the characteristic of the curler may change with time, or of a filling material leaking or otherwise eroding therefrom; and in similar manner an improved clip is disclosed for use in association with the curler when wound into the hair, which clip is readily and easily placed over the curler and the hair wound therearound.

The hair-curling apparatus described herein thereby overcomes the disadvantages of prior hair curlers by obviating the risk of the user spilling or splashing liquids of scalding temperatures, and by being readily and easily used in the hair, and by being readily and easily operable. To this end, there is also disclosed an optional feature which is included in many of the electric hair-setting appliances made according to this invention; which optional feature provides an indication of the readiness of the hair curlers for use when the curlers are heated to the proper temperature, and which indication is a steady-state indication of the ready status of the curlers notwithstanding any operation of the electrical heating elements associated therewith.

It is an object of this invention to provide a hair-setting apparatus having an homogeneous curler, an improved clip for use with the hair curler when wound into the hair, and an improved heating apparatus for heating the curlers including a status indicator of the readiness of the hair curlers when heated to the proper temperature.

It is the further object of this invention to provide heating apparatus for the electric hairsetter, which heating apparatus is readily and easily assembled using a minimum of labor, and which provides a consistency of assembly quality control heretofore not obtained. To this end the present invention provides a method of assembly of cabinets for electrical home appliances, and teaches an assembly step, and the design of the apparatus so as to facilitate the assembly step, with the savings and economy as aforesaid.

BRIEF DESCRIPTION OF THE DRAWINGS These and other features, objects and advantages of the present invention will become more obvious in the following detailed discussion thereof, in association with the annexed drawings, in which:

FIG. 1 is a perspective view of an electric hair setter according to this invention with the cover shown in exploded manner, and with the cover and several curlers shown in place in ghost lines.

FIG. 1A is a plan view of the electric hairsetter of FIG. 1 with the cover removed.

FIG. 2 is a perspective view of the heating-element portion of the electric hairsetter according to this invention.

FIG. 3 is a perspective view from beneath, of the toppanel insert of the electric hairsetter of FIG. 1.

FIG. 4 is an exploded assembly view, in perspective from beneath, showing the assembly of the heating-element portion to the top panel.

FIG. 5 is a sectional view of the top panel taken along the line 5-5 in FIG. 1A.

FIG. 6 is a sectional view of the top panel taken along the line 6-6 in FIG. 1A.

FIG. 7 is a plan view of the heating-element portion of the electric hairsetter of this invention.

FIG. 8 is a sectional view of the heating-element portion of the electric hairsetter of this invention taken along the line 8- 8 of FIG. IA.

FIG. 9 is a side view of the heating-element portion of the electric hairsetter of this invention taken along the direction ofthe arrow 9 in FIG. 1A.

FIG. 10 is a perspective view of the base portion of the electric hairsetter of FIG. 1.

FIG. 11 is a side sectional view of the base portion of the electric hairsetter of this invention taken along the line 11- 11 in FIG. IA.

FIG. 12 is an exploded assembly drawing showing the assembly of the base portion to the assembled heating element and top panel.

FIG. 13 is a schematic of the electric circuit of a typica electric hairsetter according to this invention.

FIG. 14 is a perspective view in partial cutaway of the secondary, time delay thermostat of this invention.

FIG. 15 is a perspective view of a typical hair curler according to this invention.

FIG. 16 is a top view of the hair curler of FIG. 15.

FIG. 17 is a sectional view of the hair curler of FIG. 15 taken along the line 17-17 of FIG. 16.

FIG. 18 is a plan view of the hair curler clip according to this invention.

FIG. 19 is a plan view of the hair curler clip of FIG. 18 showing the clip in position over a hair curler.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

The detailed description hereafter is made in association with the specific embodiment of the electric hairsetter shown in the drawings, which is a preferred embodiment of the hairsetter. The embodiment shown is a production model, which contains certain features not found on certain other, lower priced, production models; specifically, the curler-ready indicator light and twice as many heating posts with a longer, turned, heating element. The detailed description is, therefore, not intended to be limiting but a complete and full disclosure of all of the features of the invention.

The hairsetter, shown generally at 10, comprises a base 12, a top panel 14, and a plurality of posts designated generally at 16. Each of the posts is adapted to have a curler, designated generally at 18, placed thereover. A cover 20 is adapted to fit over the posts 16 and curlers 18 so as to protect the curlers and posts. An on-off switch 22, an on-off indicator light 24 and a curler-ready indicator light 26 are installed in a front panel 28 which, in this case, is a down-tumed lip portion of the top panel 14. An out-turned side lip portion 30 is provided on each side of the base 12 for purposes of appearance, and to facilitate the portability of the electric hairsetter.

It will be noted that the posts are of three different sizes, which may conveniently be referred to as small, medium and large respectively; representative ones of each being indicated at 32, 34 and 36 respectively. In like manner, the curlers 18 are of various sizes so as to cooperate with the different size posts, as is discussed in greater detail hereafter.

The basic construction of the electric hairsetter of this invention, exclusive of the cover therefor and of the electrical wiring installed within the cabinet thereof, comprises three major components. They are the heating-element portion 38 including the posts 16, shown in perspective in FIG. 2; the top panel insert 14, shown in perspective view from beneath the panel in FIG. 3; and the base portion 12, shown in perspective view in FIG. 10. The assembly of the three major portions of the electric hairsetter discussed above, is shown in FIGS. 4 and 12; and basically comprises first the assembly of the heating-element portion to the top panel portion in the manner described in greater detail hereafter, and then the assembly of the base to the preassembled heater element and top panel portions, which latter assembly step is also described in greater detail hereafter. The electrical wiring, all of which is concealed within the base and beneath the top panel, is installed in the conventional manner using spade clips or other simple wiring devices, and at convenient times during the assembly of the hairsetter of this invention. The wiring steps are not discussed in any detail in this application, although a representative circuit is discussed hereafter.

The heating-element portion 38 is shown particularly in FIGS. 2, 7, 8, and 9. It comprises a plurality of heating posts 16 as discussed hereafter, which heating posts extend upwardly from base 40 of the heating-element portion 38. Beneath the base 40 is a heating-element 42 having ends 44 suitable for having electrical connections made thereto extending from beyond the left end of the base 40 as viewed in FIG. 7. The posts 16, base 40, and the heating element 42 and its surrounding sheath 45 may conveniently be a single-piece casting of aluminum or alloys thereof, or other suitable materials; with the heating element 42 being placed in a mould before the casting operation. The unitary construction of the heating element portion 38 of the hairsetter provides easy and rapid heat distribution from the heating element 42 when that element is in operation. The heating-element 42 may be any of the well known types, such as Calrod, and is of the type which can be set into a mould as stated above so as to be cast into the molten aluminum or other material without injury or deformation to the heating-element.

Many other forms of the heating-element portion 38 of the hairsetter of this invention may be had. For example, in another hairsetter made according to this invention, but with only half the number of heating posts as in the specific embodiment illustrated, the heating-element portion comprises only half of the heating-element portion 38 illustrated, and the heating element 42 extends from one side thereof to the other so that electrical connections are made at opposite ends of the base rather than at the same end of the base as illustrated; For purposes of appearance, and as well to provide some protection to the material of the heating-element portion and particularly the posts, the upper surface of the base 40 and the posts 16 may be coated with a melamine urea alkyd or other suitable paint which will not bake off, bubble or deform during the heating operation. Alternatively, the posts and the upper surface of the base 40 of the heating-element portion 38 may plated.

In another embodiment of the heating-element portion 38 of the electric hairsetter according to this invention, the posts 16 may be separately cast, or cast with mould inserts, so that the amount of material used in the posts-specially the medium and large sized posts 34 and 36 may be less. However, in that embodiment of the invention, while the overall amount of material in each of the posts may be substantially identical tion 38 is substantially planar, apart from the posts, and from the heating-element and sheath on the underside. Most particularly, the base 40 is of substantially even thickness about its periphery and especially in the areas as discussed hereafter. It will also be noted that the right hand comers of the base 40 as viewed in FIG. 7 have a stepped appearance when viewed from above. Thus, at each of the stepped corners, there appears a first comer 46, followed by comers 48 and 50 which are progressively further to the rear of the front comer 46 and outwardly therefrom on each side. Near the other comers 52 of base 40 there is an indent 54 formed in each side of the base. The indents 54 are set into the sides of the base forwardly of the corners 52, (assuming the right end of the base as viewed in FIG. 7 to be the front and the left end to be the rear for purposes of this discussion) and are of substantially rectilinear configuration. It may be noted that the side-to-side dimension of the base 40 rearwardly of the indents 54 is less than the side-to-side dimension of the base 40 forwardly of indents 54, and indeed the latter dimension is as taken from and to the comers 50 across the base 40.

On the underside of the top panel 14 there are formed four downwardly extending legs 56, 58, 60 and 62. Legs 56 and 58 are closest to the front panel 28 formed in the top panel 14, and the legs 60 and 62 are opposed respectively to legs 58 and 56. Formed on the inside of each of the legs near the tops thereof are lugs 64 which define indents 66. The indents 66 extend upwardly along the legs 64 to the underside of the top panel 14. The back sides of legs 60 and 62 are shaped so as to correlate with the underside surface of the base 12 in a manner discussed hereafter.

Formed in the top panel 14 are a plurality of holes 68, the placing and diameters of which are chosen so as to relate to and accommodate the posts 16 of the heating element portion 38, in a manner particularly as illustrated in FIG. 1. Also formed in the underside of the top panel I4 is a depression 70 which does not extend entirely through the thickness of the top panel 14. The top panel 14 also has on its underside a plurality of stiffening ribs 69 which contribute to the rigidity of the panel and which extend from front to back and side to side in the areas of the underside of the panel free from and between the holes 68. Also formed around the outer periphery of the top surface of the top panel 14 is a ridge 71 which assists in locking and positioning the cover 20 when in place.

Through the front panel 28 there are formed holes 72 and 74 each of a shape and dimension suitable to receive certain of the electrical components, that is to say, the on-ofi switch 22 and on-off indicator light 24 in hole 72 and the curler-ready indicator light 26 in hole 74. The precise electrical details, and the use of the indicator lights 24 and 26, are discussed with respect to the embodiment of the electric hairsetter illustrated in the drawings; but are not relevant to the invention as disclosed herein.

In any event, it will be noted from FIG. 4 that the assembly of the heater element portion 38 to the top panel 14 requires that the heater element portion 38 be aligned with the posts 16 thereof in an imminently correlating position with the holes 68 formed in the top panel 14. The heater element portion 38 is assembled to the top panel 14 by inserting the posts 16 through the holes 68 and by having the heater element portion 38 so positioned with respect to the top panel 14 that indents 54 surround the lower portions of legs 56 and 62 and corners 46 are in proximate relationship to legs 58 and 60. It will be noted that for such a relationship, and in order to have the posts 16 centrally located with respect to their respective holes 68 upon final assembly of the heater element portion 38 to top panel 14, it is necessary that the diameters of holes 68 each respectively be sufficiently large as to allow an initial, offcenter relationship of the posts 16 to the holes 68 so as to accommodate the assembly step.

As the base 40 of the heater element portion 38 is brought into close proximity with the underside of the top panel 14, the heater element portion 38 is offset so that the comers 48 of the base 40 move over the top side of the lugs 64 and the comers 50 butt against the edge surfaces of legs 58 and 60. At the same time, corners 76 at the rearward edges of indents 54 in base 40 move so as to overlie the lugs 64 in legs 56 and 62. Thus, there is formed a mechanical attachment of the heater element portion 38 to the top panel 14; and to complete the assembly and prevent further offsetting of the heater element 38 with respect to top panel 14, a small pin 78 is driven through hole 80 formed in base 40 and into the depression 70 formed in the underside of top panel 14.

In summary, therefore, the mechanical attachment of the heater element portion 38 to the top panel 14 is such that up and down movement of the heater element portion with respect to the panel is limited by the relationship of the thickness of base 40 to the height of indent 66 of each of the legs; front-to-back motion of the heater element 38 with respect to the top panel 14 (relative to the hairsetter cabinet, taking front panel 28 as being in the front) is limited by the relationship of the comers 48 and the portion 49 of base 40 behind comers 48 coacting with legs 58 and 60, and the corners 76 and the portions of base 40 between the comers 76 and 52 on each side coacting with legs 56 and 62; and sideways motion of the heater element portion 38 with respect to the top panel 14 is limited by the cooperation of the holding pin 78 through base 40 of the heater element portion 38 with the depression 70 on the underside of top panel 14.

An additional advantage in the assembly of the heater element portion 38 to the top panel 14 as discussed above is that no screws or other unsightly mechanical holding means may be seen from above the top panel 14. In addition, as appears immediately hereafter, the assembly of the base to the preassembled heater element portion 38 and top panel 14 is from beneath so that the assembled cabinet of the electric hairsetter according to this invention has no visible assembly or mechanical holding means when viewed from above or from the sides; and yet the assembled cabinet may be readily and easily disassembled for purposes of service.

The assembly of the top panel 14 and heater element portion 38 to the base 12 is discussed below with particular reference to FIGS. 10, 11 and 12. Within the base 12 and extending upwardly from the bottom thereof are two bosses 82 and 84. Near the rear of the base 12, and towards each of the comers thereof, are two detents 86 and 88. The bosses and detents may conveniently be moulded in the base during its manufacture. The shape and spacing of the legs 60 and 62 which depend downwardly from the underside of top panel 14 are such that the legs mate with and are drawn into detents 86 and 88. Thus, for the particular model of the electric hairsetter illustrated in the drawings, the assembly of the top panel l4 and the heater element portion 38 to the base 12 is simply a matter of mating the base to the assembled top panel and heater clement portion, and inserting screws to extend through bosses 82 and 84 and into threaded holes 90 and 92 formed in the underside of the base 40 of heater element portion 38. The legs 56 and 58 sit against the upper side of the bottom of base 12; and the heights of each of legs 56, 58, 60 and 62, and of bosses 82 and 84, are such that when the top panel and heating-element portion are drawn down by the screws extending through bosses 82 and 84, a firm mechanical fit of the base to the other parts of the hairsetter is assured.

Slits 94 are formed extending through the bottom of base 12 to permit air circulation within the base so that, inter alia, the temperature rise of the surface on which the hairsetter is resting may be minimized, and to provide cooling within the base.

Having regard to the heater element portion 38, it should be noted that the stepped configuration at each of the right-hand corners as viewed in FIG. 7 is such that the portion 47 to the left of corner 46 and the portion 49 to the left of comer 48 act in similar manner to the indents 54 and that portion of the edge of the base 40 of the heater element portion 38 between corners 76 and 52 on each side thereof. Additionally, it has been noted that the stepped leading edge 51 which extends inwardly from each of corners 50 acts as a stop as each edge 51 butts against legs 58 and 60 during the assembly of the heater element portion 38 to the top panel 14 as aforenoted. Obviously, if the legs 58 and 60 were to be moved further to the left when viewed from beneath as in FIG. 3, indents similar to indents 54 could be formed in the appropriate places at the edges of base 40 of heater element portion 38 instead of corners 46, 48 and 50 as previously described. In like manner, the stop means or leading edge 51 could be formed either as indicated, or behind indents 54, or behind other indents formed instead of corners 46, 48 and 50 as previously stated.

Before the base is assembled to the preassembled top panel and heater element portion, the electrical wiring is installed so as to be in position when the cabinet, (i.e. top panel 14 and base 12) is assembled. A typical circuit, and the one which is used in the model of the electric hairsetter illustrated in the drawings, is shown in FIG. 13. In this circuit, there are included the heater element 42, the on-ofi switch 22, the on-off indicator light 24, and the curler-ready indicator light 26. Also in the circuit of FIG. 13 are the primary or operating thermostat 96 and a secondary thermostat 98, which is described in greater detail hereafter. A plug is provided to connect the electric hairsetter to a suitable power source. The on-off switch 22 and on-off indicator light 24 are conveniently installed in an assembly 102 which is inserted through hole 72 in the front panel 28 as illustrated in FIG. 4. The curler-ready indicator light 26 is a separate assembly and is inserted through hole 74 in the front panel 28.

The primary thermostat 96 is physically mounted beneath the base 40 of heater element portion 38 of the electric hairsetter, as is illustrated in FIGS. 4 and 12. The secondary thermostat 98 is also physically mounted beneath the base 40 as discussed hereafter.

The operation of the electric hairsetter of this invention is as follows. After the electric plug 100 is connected to a suitable power source, the switch 22 is operated to the on position. It will be noted that operation of the switch 22 to the on position is such that the on-off indicator light 24 is then connected across the power source in parallel with the heating element 42 which is in series with the primary thermostat 96. It will also be noted that the series connection of the secondary thermostat 98 and the curler-ready indicator light 26 is also in parallel across the power source.

Assuming the electric hairsetter to be below its operating temperature when first turned on, the heating cycle of the electric hairsetter is as follows. The primary thermostat, mounted as it is immediately below the base 40 of the heater element portion 38 and in heat-conducting relationship thereto, senses that the temperature of the heater element portion 38 is below operating temperature and closes so that power is applied to the heating element 42. As the heating element 42 heats up, heat is conducted from it by the base 40 to the posts 16. At this time, it is presumed that the curlers 18 which are discussed in greater detail hereafter are in place over the posts 16. Since the heater element 42 is a constant resistance device, as long as the primary thermostat 96 remains closed the heater element will continue heating and heat will continue to be conducted away from the heater element to the posts 16. However, when the posts 16 reach a predetermined temperature, the primary thermostat 96, being adjusted to open at that predetermined temperature of the posts by virtue of its own heat-conducting relationship to the base 40, turns off and the heater element 42 no longer continues to heat. However, as heat is lost from the posts 16 and base 40 of the heater element portion 38 of the electric hairsetter to the extent that the temperature sensed by the primary thermostat reaches a lower predetermined temperature, the primary thermostat again turns on and heat is again conducted to the posts 16 away from the heating element 42. The on-off indicator light 24 remains illuminated during cycling of the primary thermostat 96 and the heating element 42.

Because the plastic curlers 18, which are in position over the posts 16 during the heating operation, are of a different material than that of the posts, their rate of heating characteristicand heat retention characteristic are different than those of the posts. One of the objects of this invention, as aforenoted, is to provide a curler-ready indication which is independent of the operation of the heating element per se. Thus, there is no indicator light or other device which is series connected to the heater element and which goes out or extinguishes when the heater element is disconnected by the action of the primary thermostat 96. Neither is there provided on each curler 18 fitted over the posts 16 a temperature change indicator which indicates, by means of the change of color of a paint dot, a temperature of the curler above a predetermined temperature at which the paint dot changes color. Rather, this invention provides an indicator light 26 which is illuminated when the curlers 18 over posts 16 have reached their operating temperature, and whose operation is controlled by the secondary thennostat 98 in a manner described hereafter.

The secondary thermostat 98 is shown in greater detail in FIG. 14. As discussed earlier, the secondary thermostat is mounted on the underside of the base 40 of the heater element portion 38. However, unlike the primary thermostat 96, the secondary thermostat 98 is not mounted in direct heat-conducting relationship to the base 40; but rather, the secondary thennostat 98 is mounted in a manner so as to approximate the heating action of the curlers 18. To this end, the secondary thermostat 98 is mounted in a block of material similar to the material of the curlers 18, that is to say, a plastic material. The block of material 104 has a recess 106 at one end thereof through the thickness of the block, and a hole 108 extends from the recess to the other side of the block through the thickness thereof to facilitate mounting of the secondary thermostat 98 to the base 40. The thermostat itself comprises a bimetallic thermostat element 110 which is electrically connected through rivet 112 at its inner end, and is adapted to touch the contact rivet 114 at its outer end so as to complete an electrical circuit. For purposes of clarity, no electrical wiring is shown in FIG. 14.

It will be noted that the portion of the block 104 on which the thermostat element 110 is mounted is substantially I-I- shaped having legs 116 and 118 and crossweb 120 through which rivets I12 and 114 extend. When the secondary thermostat 98 is mounted beneath base 40 of the heater element portion 38, it is mounted so that the bimetallic element 110 is on the side of web 120 furthest from the underside of the base 40; that is to say, the secondary thermostat 98 is mounted in an upside-down fashion with respect to the manner in which it is illustrated in FIG. 14.

Setscrew 122 is adapted to screw into and out of the web 120 of block 104 beneath the bimetallic element 110. A hole is formed in the bimetallic element 110 to provide access to the head of setscrew 122, and the diameter of the setscrew is greater than the diameter of the hole. The bimetallic element 110 is spring-biased against setscrew 122, so that raising or lowering of the setscrew will adjust the amount of gap between the outer end of element 110 and the contact rivet 114, and will therefore adjust the operating characteristic of the thermostat. In other words, by properly adjusting the setscrew 122, the characteristic of the thermostat can be altered so tha the thermostat closes at any given temperature or heat condition. It the setscrew 122 is adjusted upwardly i.e., with reference to the web 120 as shown in FIG. 14 more heat must be absorbed by the bimetallic thermostat element 110 before the element bends sufficiently to close the gap and to touch the contact rivet 114. i

It has been noted that the block 104 is of a plastic material which has the same or similar characteristics to the material of rollers 18; and it has also been noted that the thermostat element 110 is not in direct heat-conducting relationship to the secondary thermostat 98, the heat absorption characteristic of the rollers 18 over the posts 16 can be closely approximated by the heat absorption characteristic of thermostat element 110. Since, under carefully controlled conditions of voltage and ambient temperature, it can be determined what time lapse from initial energization of the heating element 42 is required for the curlers to reach a predetermined temperature suitable for winding into the hair as aforesaid, it is therefore possible, under the same conditions of voltage and ambient temperature to set the characteristic of the secondary thermostat 98 to close or turn on after the same time lapse or interval. It will be noted from the circuit of FIG. 13 that when the secondary thermostat 98 closes, the curler-ready indicator light 26 is energized; and therefore, a simple adjustment of the setscrew 122 under predetermined voltage and ambient temperature conditions with the electric hairsetter of this invention in operation so that the secondary thermostat 98 closes after a predetermined length of time will assure that, in future operations, perhaps under other voltage and ambient temperature conditions, the curler-ready indicator light 26 will not become energized until such time as the curlers are at the proper temperature. A separate, independent and reliable indication of the ready state of the curlers l8 placed over the posts 16 is thereby provided.

The operation of the secondary thermostat 98 after it closes is independent of the operation of the primary thermostat 96; so that the primary thermostat 96 may cycle and turn the heating element 42 on and off as conditions may warrant, whereas the heat conditions detected by the secondary thermostat 98 are generally such that it does not cycle during normal operation of the electric hairsetter. That is to say, while the operation of the heating element 42 is cyclic due to the heat loss by transmission, conduction and radiation from the metallic base 40 and posts 16 and the heat transmission thereto depending upon the condition of element 42, all as sensed and controlled by the cycling or primary thermostat 96; the operation of the secondary thermostat 98 is more closely related to the heat or temperature conditions of the rollers 18 which, once hot, retain their heat and give their heat up much less readily than the metallic posts over which they are placed. Therefore, as stated above, because the block 104 of secondary thennostat 98 is of a plastic material having the same or similar characteristics to that of the roller, the heat conditions as they relate to the bimetallic thermostat element approximate those of the rollers, and as long as the rollers are retaining their heat within limits, with any loss thereof being made up by the cyclic operation of the heating element 42, so does the secondary thermostat 98 remain closed and the curler-ready indicator light 26 remain illuminated.

It should be mentioned that the heat absorbed by each of the curlers 18 as it is in place over its respective post 16 is transferred to the curler from the post by radiation from the outside surface of the post, conduction where the curler touches the post or is closely associated therewith, and to some extent by convection. Further, as the curlers absorb heat, they may also lose heat. Thus, the curlers which are placed over posts in each corner can radiate heat outwardly in two directions (vectorially), which directions are in the opposed senses to the curlers next adjacent each of the comerplaced curlers; and in like sense, each of the curlers situated between the comers and on the outer extremity of each of the rows of curlers radiates heat in one direction (vectorially). The heat radiated in such manner is, in essence, lost. The curlers also radiate heat in the other directions, as do all of the curlers, but this results in heat transfer from one curler to another, and is a minor phenomenon. The net effect of heat loss by radiation of the curlers, particularly those on the outside, is that those curlers may be slightly lower in temperature (that is, amount of heat absorbed) than those curlers on the inside; but because of the low-heat loss characteristic of the material of the curlers, this effect is small. Thus, it is possible to provide a single indication such as the curler-ready indica tor light 26 which is activated by the secondary thermostat 98 in the manner discussed above, which indication is sufficient to indicate the ready status of all of the curlers.

Yet another way in which a single curlerready indication may be provided is by placing on the upper surface of the top panel 14 a dot of temperature sensitive paint, such as paint dot 99. One suitable temperature sensitive paint is sold under the trade name Chromonitor BC" by Tempil Corporation of New York City, and has the characteristic that the color of the paint dot changes from red to black at approximately 150 F. The color of the paint dot reverts back upon cooling. Thus, by properly positioning the dot of temperature sensitive paint on the upper surface of top panel 14 so that the color change is effected when the curlers reach the desired temperature, the curler ready indication may be provided. This latter manner in which a curler ready indication may be provided is one which is less costly than the use of the secondary thermostat 98 and the curler-ready indicator light 26, and is usually provided on models of the electric hairsetter made according to this invention which provide only half the number of heating posts and curlers as the model illustrated in the drawings.

Turning to FIGS. 15, 16 and 17, it will be seen that the hair curler of this invention comprises a moulded outer shell 124 and a moulded inner shell or insert 126. Formed on the outer periphery of the curler 18 are a plurality of posts 128 which are intended to wind into the hair when the curler is in use, so as to assist in positioning the curlers and maintaining them in position. Of course, the number of posts 128 which are formed on the outside of the roller is dependent upon the size of the roller, that is to say, the diameter and thus the circumference of the roller. The posts 128 also facilitate the handling of the curlers 18 since the posts are fairly sharp with respect to the body of the curlers, and have a low mass of material, and are therefore not usually as hot as the body of the curlers.

It is a feature of the curlers according to this invention that the shell thickness of the curler, which is the combined thickness of insert 126 and outer shell 124, is constant from size to size of the curlers, and is nearly constant from top to bottom in each respective curler. Each curler is moulded of a plastic material having the characteristic that the material of the curler will not deform at the temperatures at which the curler is intended to be used, and having the further characteristic that heat absorbed by the curler is lost at a slow rate when the curler is in use. Several of the plastic materials which have been found to be suitable are acetyl resins, polyacetylresins, and homopolymers or copolymers thereof, and nylon. Of the former, two materials which can be used are, for example, "Celcon (a trade mark of the Celanese Polymer Company) and Delvin (a trade mark of E. l. du Pont de Nemours Corporation). It will be noted that each curler is formed with an inwardly facing conical depression 130 formed in its upper end and an inward step 132 formed in its lower end. The conical depression 130 at the upper end of the curler surrounds a hole 131 formed therein so that communication to the interior of the curler is possible from each end thereof. The end shapes of the curler are so provided to make easier use of the clip illustrated in FIGS. 18 and 19 as discussed hereafter.

It should also be mentioned with respect to the curlers 18 that they may be moulded as a single piece rather than having an outer shell and an insert, but the two-piece moulding provides economy in the manufacture of the curlers by allowing much faster cycles in the moulds and by precluding chances of mould error such as hot spots, by having a lower amount of material in the mould than would otherwise be the case. To facilitate retention of the insert 126 by the outer shell 124 to each curler 18, a small ridge 134 is moulded in the lower inner surface of each outer shell 124.

The clips 136 are such that any clip 136 may fit over any curler 18 because of the constant shell thickness of curlers l8 irrespective of their diameter as discussed above. Each clip 136 is formed having a straight back portion 138 forming one leg of the clip, a somewhat sinuous front portion 140 forming the other leg of the clip, and a loop 139 at the closed end of the clip 136 between and joining the legs 138 and 140. The

material of the clip is such that the legs 138 and 140 are yieldable. The ends of each of legs 138 and 140 are coated with a soft, rubberlike cushioning material 142 so as to protect them, and the user, from any sharp edges which may be formed. Each clip 136 will not only fit each of the curlers 18 irrespective of their diameter but will fit over each curler from each direction. Thus, when the user has wound a curler 18 into the hair, the clip 136 may be placed over the curler and the hair wound thereon from either end thereof so as to securely hold the curler in place. The shapes of the ends of the curlers 18 at and 132 facilitate easy entrance of the leg of the clip to the interior of the curler without the necessity of spreading the legs 138 and 140 of the clip 136 prior to the application of the clip to the curler.

In most of the hairsetters of the prior art as previously discussed there have been provided different sized clips to cooperate each respectively with the different sizes of curlers provided. These clips fit across a diameter of the curler with which the clip is used, and are disadvantageous in that the placing of the clip over a curler along a diameter thereof is sometimes very difficult; and further that, by their nature, the ends of the clips tend to interfere with the hair wound over the curler as the clip is being positioned. The clip 136 of the present invention, on the other hand, is such that its positioning over any of the curlers is readily effected as discussed above and illustrated in FIG. 19 without undue disturbance or interference of the outside leg of the clip with the hair wound about the curler; and further, that only one set or ridge may form in hair immediately beneath the clip on each curler, whereas two sets or ridges may be formed in the hair beneath the two legs of an outside-fitting clip over any curler as aforesaid. In addition, by providing a clip 136 which will cooperate with any curler l8 irrespective of its diameter, certain economies in production and assembly of the hairsetter according to this invention may be effected since only a specific number of clips need be provided without having to count, sort and collate a number of various clips of various sizes as has previously been the case, and without the necessity to denote various sized clips by the application of different colors, one to each size respectively, and the additional tooling and color application manufacturing steps required therefor.

We claim:

1. in an electric hairsetter having a cabinet comprising a base portion and a top panel portion, and a heater element portion with a substantially planar base having a plurality of posts thereon secured within said cabinet with said posts extending upwardly through a plurality of cooperating holes formed in said top panel portion, the improvement comprising:

a plurality of legs formed on the underside of said top panel portion, and an indent formed on the inside facing surface of each of said legs near the top thereof and extending upwardly from a lug defining said indent;

indents formed in the edges of said substantially planar base of said heater element portion so that each indent is respectively in cooperating relationship with one each of said plurality of legs formed on the underside of said top panel portion, so as to allow relative sideways motion of said heater element portion to said top panel portion when said indents in said base are in coupled relationship respectively to said indents formed in each of said legs; and stop means formed in said base of said heater element portion to prevent said relative sideways motion in one direction; and

pin means cooperating with said base of said heater element portion and said top panel portion to prevent said relative sideways motion, said pin means extending through a hole fonned in said base portion of said heater element portion and into a cooperating depression formed in the underside of said top panel portion, the alignment of said lastmentioned hole and said depression being cooperative with said pin means only when said relative sideways motion of said heater element portion to said top panel portion is at'its extreme in said one direction as defined by said stop means.

2. In the apparatus of claim 1, said stop means being formed in said base portion in at least one edge thereof and proximate an indent formed in an edge of said base portion.

3. In the apparatus of claim 2, detents formed in said base portion of said cabinet to cooperate with at least a pair of said plurality of legs formed on the underside of said top panel portion, and at least one boss upstanding from said base and adapted to have screw means extending therethrough to draw said heater element portion and said top panel portion down to said boss and so as to encourage cooperation of said last mentioned pair of legs with said detent means upon operation of said screw means.

4. An electrically heated hairsetter comprising:

a cabinet having a base and a top panel portion, and an electric heater element portion having a base and adapted to fit within said cabinet so that the base of said heater element portion is in sideways motion cooperative relationship with legs depending downwardly from beneath said top panel portion; with indents in. said base of said heater element portion adapted to move within indents formed in said legs, stop means to prevent relative sideways motion of said heater element portion to said top panel portion in one direction at a predetermined extreme, and pin means cooperating with the underside of said top panel portion and the base of said heater element portion to rigidly lock the one to the other when said relative sideways motion is at said extreme;

said base of said cabinet being adapted to be fixed to the said locked heater element portion and top panel portion by screw means extending through said base into the base of said heater element portion;

said heater element portion having a heating element cast within its base, and having a plurality of posts extending upwardly through a plurality of cooperating holes formed in said top panel portion, each of said posts being adapted to receive a hair curler thereover and to heat the same when said heating element is connected to a suitable electric power source; and

indicator means on said top panel portion to provide a steady-state indication of the curler-ready status of said curlers only when said curlers have reached a predetermined temperature condition.

5. The hairsetter of claim 4 wherein said indicator means comprises at least one dot of temperature sensitive paint adapted to change color at a predetermined temperature having a direct relationship with said predetermined temperature condition of said hair curlers; said at least one dot of paint being placed on said top panel portion of said hairsetter in a position so as to be visible when said curlers are in place over said posts.

6. The hairsetter of claim 4 wherein said indicator comprises a thermostat controlled light mounted in said top panel portion, the thermostat for controlling said light being mounted in said cabinet on the underside of said base of said heater element portion in a position remote from said heating element;

said thermostat comprising a supporting block of material of similar heat adsorption characteristic to that of a curler adapted to be received on one of said posts, said block having a bimetallic thermostatic element mounted thereon on the side thereof away from said underside of said base of said heater element portion, said thermostatic element being adapted to open and close at predetermined temperatures;

means associated with said thermostatic element to alter the closing characteristic thereof;

said light being electrically in series with said thermostat across a suitable electric power source.

7. The apparatus of claim 6 wherein said means to alter the closing characteristic of said thermostatic element is a set screw extending into said supporting block beneath said thermostatic element. 

1. In an electric hairsetter having a cabinet comprising a base portion and a top panel portion, and a heater element portion with a substantially planar base having a plurality of posts thereon secured within said cabinet with said posts extending upwardly through a plurality of cooperating holes formed in said top panel portion, the improvement comprising: a plurality of legs formed on the underside of said top panel portion, and an indent formed on the inside facing surface of each of said legs near the top thereof and extending upwardly from a lug defining said indent; indents formed in the edges of said substantially planar base of said heater element portion so that each indent is respectively in cooperating relationship with one each of said plurality of legs formed on the underside of said top panel portion, so as to allow relative sideways motion of said heater element portion to said top panel portion when said indents in said base are in coupled relationship respectively to said indents formed in each of said legs; and stop means formed in said base of said heater element portion to prevent said relative sideways motion in one direction; and pin means cooperating with said base of said heater element portion aNd said top panel portion to prevent said relative sideways motion, said pin means extending through a hole formed in said base portion of said heater element portion and into a cooperating depression formed in the underside of said top panel portion, the alignment of said last-mentioned hole and said depression being cooperative with said pin means only when said relative sideways motion of said heater element portion to said top panel portion is at its extreme in said one direction as defined by said stop means.
 2. In the apparatus of claim 1, said stop means being formed in said base portion in at least one edge thereof and proximate an indent formed in an edge of said base portion.
 3. In the apparatus of claim 2, detents formed in said base portion of said cabinet to cooperate with at least a pair of said plurality of legs formed on the underside of said top panel portion, and at least one boss upstanding from said base and adapted to have screw means extending therethrough to draw said heater element portion and said top panel portion down to said boss and so as to encourage cooperation of said last mentioned pair of legs with said detent means upon operation of said screw means.
 4. An electrically heated hairsetter comprising: a cabinet having a base and a top panel portion, and an electric heater element portion having a base and adapted to fit within said cabinet so that the base of said heater element portion is in sideways motion cooperative relationship with legs depending downwardly from beneath said top panel portion; with indents in said base of said heater element portion adapted to move within indents formed in said legs, stop means to prevent relative sideways motion of said heater element portion to said top panel portion in one direction at a predetermined extreme, and pin means cooperating with the underside of said top panel portion and the base of said heater element portion to rigidly lock the one to the other when said relative sideways motion is at said extreme; said base of said cabinet being adapted to be fixed to the said locked heater element portion and top panel portion by screw means extending through said base into the base of said heater element portion; said heater element portion having a heating element cast within its base, and having a plurality of posts extending upwardly through a plurality of cooperating holes formed in said top panel portion, each of said posts being adapted to receive a hair curler thereover and to heat the same when said heating element is connected to a suitable electric power source; and indicator means on said top panel portion to provide a steady-state indication of the curler-ready status of said curlers only when said curlers have reached a predetermined temperature condition.
 5. The hairsetter of claim 4 wherein said indicator means comprises at least one dot of temperature sensitive paint adapted to change color at a predetermined temperature having a direct relationship with said predetermined temperature condition of said hair curlers; said at least one dot of paint being placed on said top panel portion of said hairsetter in a position so as to be visible when said curlers are in place over said posts.
 6. The hairsetter of claim 4 wherein said indicator comprises a thermostat controlled light mounted in said top panel portion, the thermostat for controlling said light being mounted in said cabinet on the underside of said base of said heater element portion in a position remote from said heating element; said thermostat comprising a supporting block of material of similar heat adsorption characteristic to that of a curler adapted to be received on one of said posts, said block having a bimetallic thermostatic element mounted thereon on the side thereof away from said underside of said base of said heater element portion, said thermostatic element being adapted to open and close at predetermined temperatures; means associated with said thermostatic element tO alter the closing characteristic thereof; said light being electrically in series with said thermostat across a suitable electric power source.
 7. The apparatus of claim 6 wherein said means to alter the closing characteristic of said thermostatic element is a set screw extending into said supporting block beneath said thermostatic element. 